People reports that the condition that Kate Middleton was hospitalized with just days ago, hyperemesis gravidarum (HG), is more likely to develop in women who are carrying multiples. According to People, HG is "characterized by debilitating nausea and vomiting that severely inhibits a woman's ability to eat or drink and results in significant weight loss." It affects up to only 2 percent of pregnant women.

"It's the body reaction to the pregnancy hormone. Some women who are very sensitive to it can start feeling nauseated early on in pregnancy and it will provoke them to take the test," Dr. Dagni Rajasingam, spokesperson for the Royal College of Obstetricians, said.

Treatments for the condition include IV fluids, anti-nausea medications and sometimes, feeding tubes. Dr. Marlena Fejzo, a UCLA professor of research and leading expert on HG, spoke about the idea that the likelihood for this condition increases with multiple babies: "The leading theory is that the cause is hormonal. Obviously when you're carrying twins those hormones are higher, so if you have a problem processing those hormones then you're more likely to feel worse."

Dr. Fejzo goes on to explain that this condition can sometimes give the mother post-traumatic stress "from the severe, prolonged nausea at a time when you know you're supposed to give your baby nutrients and you just can't. It's hell for these women – like going through a war."

But what about the baby? Complications include the possibility of fetal death, pre-term birth and low birth weight. Scary!

As much as we'd love multiple royal babies, we just hope that Kate and the baby(ies) make it out of this OK!